1. Field of the Invention
This invention relates to a catalyst for use in auto emission control which has improved poison resistance for long term durability and especially for an improved three-way catalyst (TWC)
2. Description of Previously Published Art
As we described in our U.S. Pat. No. 4,476,246, performance of alumina-supported platinum group metal catalysts, especially Pt-Rh or Pt-Pd-Rh TWC, could be substantially improved by doubly promoting the catalyst with ceria and the oxides of alkali metals, especially of Li. There still exists the need to produce a catalyst with an even longer term durability which requires improved poison resistance.